Hydraulic motor system

ABSTRACT

A hydraulic motor system mechanism for driving a member selectively in opposite directions and to either of a pair of positions in either direction. The mechanism comprises two pairs of double acting hydraulic cylinders with interconnecting piston rods, whereby selective pressurization of a cylinder of either pair of said cylinders effects movement of the member in one direction to a first position and pressurization of the other cylinder of the pair effects movement to a second and further position in the same direction. Pressurization of one or both cylinders of the other pair effects movement of the member to a first or second and further position in an opposite direction.

This application is a division of Ser. No. 198,917, now U.S. Pat. No.3,792,758, filed Nov. 15, 1971, in turn a continuation of Ser. No.840,667, filed July 10, 1969, now abandoned.

Reference is made to corresponding divisional applications Ser. No.314,146, filed Dec. 11, 1972 and Ser. No. 314,159, filed Dec. 11, 1972.

Briefly the invention contemplates a roller mounted tower comprising apair of spaced columns, intermediate spacing having an elevator in whicha tray is disposed and supported for reciprocal vertical movement drivenby a sprocket chain arrangement for raising or lowering cargo ladenpallets. The tray is mounted on a telescopic transport mechanism forsliding movement to either side of the tower from a retracted or neutralposition so as to insert or remove cargo laden pallets relative tostorage grids at selected positions, i.e., cells in the grids. Theinvention can be used with manual, semi-automatic, or fully automaticcontrol. The transport mechanism can extend the tray to either of twodistances or pallet positions to either side of the tower so thatstorage grids of double depth cell construction at the same level oneach side of the tower can be served.

The device is capable of handling very heavy loads albeit with atelescopic tray transport which is relatively flat and compact,comprising a combination of telescopic cantilever beams and fourhydraulic cylinders coupled to each other in a novel manner and to adrive member. Such drive member is coupled to a series of telescopicallyarranged drive members, coupled by flexible member, e.g., sprocket chainarrays in such a manner that hydraulic actuation of the first drivemember causes an additively increased actuation of the series fortelescopically extending the drive members. The combination ofactuations effects a telescopic movement of the drive members and of thebeams to transport of the pallet laden tray. Such telescopic coaction insimultaneous and reversible so as to move the tray to either side of thetower, and control of the hydraulic cylinder actuation can effect a halfor full distance of tray movement to utilize double depth storage cellsfor handling two pallets to a cell.

The drive members all nest within each other to form a compactstructure, but are not subject to cargo load nor weight stress. Suchweight stress is borne by the beams distributed at both sides of thenested drive members and substantially in the same plane to effectcompactness. A first pair of beams is secured to the tower frame while afinal pair is secured to the tray. Intermediate pairs articulate thefirst and final pairs thus described, for reversible telescopic loadsupporting effect on either side of the tower. The load carrying beamsslide with respact to each other on intermediate roller bearing arrays.

The tower is driven on a track intermediate the storage grids, therebeing two rollers supporting the tower each independently driven by anelectric motor. Accordingly, very tall towers can be utilized, albeitthe higher the tower, the higher the center of gravity. Thus, alessening of traction of either roller due to forward or rearwardpivotal forces on the tower about a roller caused by deceleration oracceleration will not affect drive of the tower since one roller or theother will inherently have traction increased when traction of the otheris decreased.

A detailed description of the invention now follows in conjunction withthe appended drawing, in which;

FIG. 1 is a front elevation showing the horizontally movable tower andthe vertically movable elevator for carrying a tray in relation to thecells of a structural storage grid at one side of the track on which thetower rolls, the tray being extensible towards and away from the planeof the paper;

FIG. 2 is an end elevation of a tower between a pair of storage gridsshowing the reversible direction of motion of the tray elevator, thetower being movable toward and away from the plane of the paper;

FIG. 3 is a plan view of a storage system having a plurality of towersin movable and parallel array with an infeed conveyor;

FIG. 4A is a front elevation of the upper construction of the tower;

FIG. 4B is a continuation of FIG. 4A showing the construction of thelower portion of the tower;

FIG. 5 is a section generally through 5--5 of FIG. 4B;

FIG. 6A is a vertical section through 6A--6A of FIG. 4A;

FIG. 6B is a vertical section through 6B--6B of FIG. 4B;

FIG. 6C is a fragmentary perspective of an upper corner of the tower;

FIG. 7 is a front elevation showing details of the fingers of amechanism for horizontally aligning pallets on the tray so as to becentralized thereon;

FIG. 8 is a side elevation of the tray on line 8--8 of FIG. 7 showingthe tray position indicator assembly;

FIG. 9 is a front elevation of the tray showing the relationship of thetelescopic drive members, support channels, support rollers and chainand hydraulic drive mechanism;

FIG. 10A is a fragmentary plan view showing the telescopic mechanism forthe tray in transported, i.e., extended condition;

FIG. 10B is a fragmentary plan view which is a continuation of FIG. 10Ashowing the remainder of the telescopic transport mechanism with thetray supported at the end thereof fully extended outwardly fordepositing a pallet in a storage cell, lifting a pallel out of a cell;

FIG. 11A is a section through 11A--11A of FIG. 10A;

FIG. 11B is a section through 11B--11B of FIG. 10B;

FIG. 12 is a side elevation of the support roller layout on a slide beamof the tray transport mechanism;

FIG. 13 is an end view of one of the support beams of the telescopictransport mechanism;

FIG. 14 is a plan view of the hydraulic system comprising respectivepairs of articulated cylinders for actuating the tray in respectivedirections transversely of the tower wherein the sub figures A, B, and Cshow progressive extension of a drive member as certain cylinders arepressurized for transport of the tray toward the left;

FIG. 15 is a view similar to FIG. 14, but wherein the sub figuresillustrate the progressive drive member positions A, B and C away fromthe tower wherein the cylinders are pressurized for extension to theright.

FIG. 16 is a diagram of the chain drive of the tray wherein sub figuresA, B, and C show central position and full left and right extensions,respectively.

GENERAL DESCRIPTION

Referring to FIG. 1, the invention comprises a tower 10 having a pair ofstructural columns 15 built up of corner angle irons and diagonal crossbraces as generally illustrated and supporting for vertical movement apallet carrier or tray elevator 10 comprising a tray 20 and capable ofvertically lifting pallets 24 carrying, e.g., boxed merchandise asillustrated, the vertical arrows indicating the reverse directions ofmotion of the elevator. The tower is movable reversibly as indicated bythe horizontal arrows, being supported as a roller 20 under each column,which rollers travel on a track 32. The lower end of the tower is thussupported and guided on track 32 while the upper end frame 33 of thetower (FIG. 6A) is guided by an angle iron member 36 between guiderollers 30 (FIG. 2) carried by the tower on arm 39.

Referring to FIGS. 2 and 3, the tower rolls between storage grids 40 and44 made up of structural members in cellular construction in a knownmanner.

A grid 40 and a grid 44 can be assembled back to back to effect aplurality of bays as illustrated in FIG. 3. Each cell can be doubledepth horizontally to hold two pallets 24 as illustrated in FIG. 3.

As seen in FIG. 2, tray 20 is extended toward the right for the purposeof moving a pallet 24 containing a load of cartons to be deposited in acell at 46. Extension of the tray is indicated in solid lines, the cargobeing stored at the full horizontal depth of the cell, i.e., towards therear. Another pallet as indicated in phantom at 46' is stored at thefront. Obviously, the same extension of the tray can be used for liftingto retrieve a pallet and its cargo. Likewise in FIG. 2, the position ofcargoes at 47 and 47' (in phantom) to the left illustrates thereversible movement of the tray 20 as indicated by the dotted arrow.

Thus the tower can move horizontally into alignment in any desiredlocation between a pair of storage grids and the tray elevator can thenmove vertically. Subsequently the tray can move transverselyhorizontally toward or away from the storage grids for depositing orretrieving loads. Obviously, vertical control of the tray elevator issuch as to place the tray initially slightly above the spaced cell beams40 in inserting a pallet and slightly below for withdrawal, finalvertical movement of a couple of inches then being had to rest thepallet or lift it. The tray is slightly narrower than the distancebetween beams 40 as noted in FIG. 5.

The members 40 are support rails on which pallets are stored, and arespaced apart a sufficient distance for tray clearance in moving up ordown between them.

FIG. 3 shows a schematic layout whereby the invention can be used for aplurality of storage grids back to back, with a track 32 intermediatesuch grids 40 and 44 formed in bays and each track being served by adiverter chute 50. Thus, a series of diverter chutes such as 50 arespaced along an infeed conveyor 55 and the diverter device 50 can divertcargo carrying pallets 24 to any chute 50 in accordance with manual orautomatic control.

Referring again to FIGS. 1 and 2, the tower carries a control panel 60and a platform 64 on which an operator may stand for manual control ofthe tower and tray. The tower and tray may likewise be controlled byautomatic electronic means from a remote console by conventionalequipment, or by computer programming.

Power for motivating the tower is derived from a pair of motors 70 (seeFIG. 4D) each driving a flanged roller 28 on track 32 via conventionalreduction gearing, the motors, rollers and gearing all being supportedby the roller shafts 76 with bracing 77 to the columns, FIGS. 4B, 5, and6B.

The base frame 75 may be made up of welded plates and structural membersas illustrated, in any conventional manner.

Referring to FIG. 1, it will be appreciated that the tower can be of anydesired height. However, the taller it is the higher the center ofgravity. This is especially true if the tray elevator 18 is at someelevated level, and cargo loaded, when the tower is moving in eitherdirection on track 32. Accordingly, assuming that the tower is startingto move from a standstill position, going to the left, the accelerationforce will cause a reduction of traction on the left hand roller.However, load remains on the right hand roller for traction effect.Similarly, when the tower slows down, the deceleration causes lesseningload on one or the other roller, depending on direction, and brakingeffect is then applied to the more heavily loaded roller. Therefore, byproviding a separate motor 70 for each roller, the traction differentialis minimized. Where a tower is set in motion or slowed down with asimultancously rising load in the tray elevator, the advantage of theindependent motor or arrangement is apparent.

The tray elevator motor 80 (FIGS. 4B and 5) is carried by the base frame75 of the tower and as in the case of the tower drive motors 70 isdisposed on a vertical axis, driving the multiple sprocket chains 90 forrotating a shaft 95 having a gear 100 at thelleft end of the shaft asshown in FIG. 4B which will be understood to mesh with the lower loop ofthe chains 90.

The shaft 95 (FIGS. 4B and 6B) has a pair of gears 105 at respectiveends keyed thereto around each of which is a tray lifting chain 110. Thechains 110 each terminate at their lower ends through a spring tensionedconnection 115 (FIG. 6B), being thus fastened to the frame of trayelevator structure 18 through the take up bolt 118 and a spring 122. Theframe of the tray elevator will be later described. By taking up on arespective bolt via the nut 123 (FIG. 6B) chain wear elongation iscompensated. Elongation due to load variation is compensated byrespective springs 122, adjusted by nut 124. The other ends of thechains 110 (FIGS. 4A, 6A) are ultimately secured at respective points124 to the tray structure 18 as later described. Chains 110 passupwardly to the top frame 33 of the tower and around idler gears 120carried on a shaft 131 having suitable bearing blocks 132 in a box likestructure comprised of heavy longitudinal beams 135 which form therigidifying top frame 33 (FIG. 4A) in conjunction with equally heavytransverse channels 140, for the columns of the tower. The bearingblocks 132 rest on the inner vertical structural iron angle members 145of the columns 15 (FIGS. 4A, 6A, 6B) specifically on cross brackets 155.

From the foregoing description it will be understood that energizationof motor 80 will raise or lower the tray elevator 10 via chains 110dependent uopn direction of motor rotation (FIGS. 1, 2, 4B, 6A, 6B)drive being had via chains 90 and shaft 95 and associated gears so thatboth sides of the tray elevator 10 have lifting force applied thereto atthe respective connections 224, FIG. 6A.

THE TRAY ELEVATOR

Referring to FIGS. 4A, 4B, 5, 6A, 6B, 7 and 8, the tray elevator 10comprises a frame having a top beam 200 (FIGS. 4A, 6A) extending betweentower columns 16 and secured at its ends on the back of a short channel202. A pair of transverse beams (FIG. 4A) or channels 205 carrytransverse guide rollers 210 that ride (FIG. 4A) on vertical members145, on tracks 212 welded thereto. The construction is symmetrical atboth ends of beam 200. A longitudinal guide roller 210 is carried ateach side of the tray elevator in a respective vertical frame channel220 which form the sides of the elevator frame structure and which aresecured at their upper ends to respective pairs of beams 205. Rollers218 ride on fixed vertical guide bars 222 (FIGS. 5, 6A) intermediatemembers 145.

The side frame members 220 are secured at their lower ends to theelevator base frame 226 FIGS. 4B, 5, 6B) and the upper flange edges arewelded to the flange edges of short channels 202 to form openings forchain passage and the plates 222 welded therein which form end chain andfastenings at 124 (FIG. 6A).

As seen in FIG. 6B the lower ends of chains 110 (one shown) are securedvia bolts 118 as heretofore mentioned, passing through cars 227 weldedinside channels 320.

The construction is symmetrical as far as the guide roller arrangementat top and bottom (FIGS. 4B, 6B) of the tray elevator is concerned inthat guide rollers 230 at the sides of column members 145 are similar torollers 210. Also, guide rollers 235 are similar to rollers 210,provided to roll on bars 222.

The elevator base frame 226 (FIGS. 4D, 5, 6B, 7, 8) comprises a box beamconstruction shown in transverse section in FIGS. 6B and 8 and in fullline front elevation in FIG. 7, being built up of plates such as 245a,245b, 245c, 245d, and channel members 245e, 245f in a rigid weldedconstruction suitable for load support. Other types of frameconstruction can, of course, be used.

The plates 245c and 245d extend longitudinally across the frame 226construction (FIGS. 7, 9 10A, 11A, 14, 15) at a central area as a mainsupport for the tray transport mechanism later described.

The side channel members 220 are secured at respective sides of the baseframe 226. The webs of such channel members 220 form the lateral sidewalls of frame 226 to some extent by being coplanar with angle ironmembers 250 (FIG. 5) which carry rollers 230.

The construction permits lift chains 110 to be nested within the flangesof the side channel members 220 as seen in FIG. 5. Also nested withinsuch flanges are hydraulic cylinders 253 (FIGS. 5, 6D, 7) pivotallysecured to the webs at 258 and having rods articulated via levers 260 torespective shafts 262 having bearing support as by pillow blocks 265secured to respective cross plates 245a and 245b of the elevator basefrom 226. The shafts are on respective sides of tray 20 and each has apair of spaced fingers 270 (FIGS. 6B, 7) which are thus rockablyactuated upon the pressurizing of cylinders 255 to engage the sides ofpallets such as 24 in order to center the pallets on the tray 20. Thefingers move in unison to the same predetermined inner limits, e.g., asmay be provided by identical positioning of identical cylinders 255 andfull movement of the piston rods, in the instant case such movementbeing one of retraction.

THE TELESCOPIC TRAY TRANSPORT

Referring to FIGS. 7, 8 and 9, the plates 245c and 245b support heavycantilever channel beams 275 on spacers 176 and secured by bolts 270,provided in plurality (FIG. 8), and these beams will be understood to bethus fixed to elevator frame 226. Lateral adjustment bolts 201 providedon side plates 283 secured to the frame 226 effect alignment andparallelism of beams 275.

Referring to FIGS. 9, 10A and 10B, three additional pairs of channelbeams 275a, 275b, 275c similar to beams 275 are provided, all coplanarand of progressively smaller size, but all cantilever load carryingbeams telescopically connected with each other and ultimately with beams275, including a final pair of channel beams 275c of smallest size.

Slide bearings 277 (FIGS. 9, 12) are secured to the beams for case ofsliding engagement and precise spacing.

All such beams except 275 carry groups of rollers 285 (FIG. 12), threerollers to a group, four groups to a beam, which rollers ride the upperand lower surfaces of the channel of the adjoining beam (FIG. 9).

The innermost pair of channel beams 275c carry angle iron beams 290 towhich tray 20 is secured (FIGS. 9 and 10B). Such support of beams 290are likewise by groups of rollers 205.

It will be apparent from consideration of FIGS. 10A and 10B that thetray 20 is supported for horizontal reversible movement away from andback to or through the tower (as represented by plates 245c and 245d)wherein the tray can extend to either side of the tower to the maximumdistance provided within predetermined limits, due care being had toprovide proper support by two roller groups 285 for all beams withinadjoining channels at maximum extension in either direction.

The driving mechanism for tray 20 for reversible motion away from andback to or through the tower comprises three nested drive members orplates 300, 305, 310 (FIGS. 4B, 9, 10A, 10B, 11A, 11B). As seen in FIG.9, the drive members are nested channel shaped plates havingprogressively wider horizontal flanges and spaced vertical flanges aswell as vertically spaced horizontal webs. The horizontal flanges ofeach drive plate are secured to the lower surfaces of a pair of channelbeams. Thus, flange pairs 300a, 305a, 310a are secured to beam pairs275a, 275b, 275c, respectively, (FIG. 9).

The drive plates may be secured to the beams by bolts (not shown) or inany other suitable manner, and are thus carried by the beams. Bracingtubes 311 which have slide bearings 312 are welded to plates 305 and310.

The drive plates are telescopically movable with respect to each other,the innermost plate 300 being driven hydraulically. Plates 305 and 310are chain driven from plate 300 as is tray 20 via angle iron beams 200,in a manner to be described.

Referring to FIGS. 10A, 11A, 14 and 15, the hydraulic drive for plate300 comprises four double ended cylinders 350, 360, 365 (FIG. 14).Cylinders 350 and 355 are welded at their rod ends to each other, at370, as are cylinders 360 and 365 welded at 375. The piston rods 355aand 360a of cylinders 355 and 360 are pivotally connected to each otherby a pin 300 having bearing support on a T-slide guide block 305. AT-slide guide bar 390 (also see FIG. 10A) is secured to fixed crossplates 245c and 45d being thus rigidly secured horizontally to theelevator base frame 226. Rod 350a of cylinder 350 is pivotally securedat 395 to cross plate 245c via plate 398 secured to plate 245c (FIG. 14)and is thus fixed to provide reaction support (FIG. 9). Rod 365a ofcylinder 365 is pivotally secured at 400 (FIG. 9) to drive plate 300.

The four cylinders are carried in a common plane and thus float as anintegral assembly having pivotal securement to the frame 226 of the trayelevator (via the cross plates 245c and 245d) and the innermost driveplate member 300, as described.

In FIG. 14, a neutral position A with all rods extended is shown whereinthe cylinders are under pressure at one side to hold such positionlocked and drive plate 300 (and tray 20) is centered between the towercolumns (FIG. 5). For such purpose hydraulic blocking is possible butpositive pressure is preferred. However, in FIG. 14 the result ofpressurizing by valving (not shown) the right end of cylinder 365 isnoted in position D; rod 365a has been shifted to the left (see arrow)carrying plate 300 with it to the left toward an intermediate positionaway from the tower. This would be the position for moving tray 20 intothe first half of the full horizontal depth of a cell, e.g., to firstpallet position 47' of FIG. 2. This is possible because of the reactionsupport at 395 and by maintaining all pistons (not shown) of thecylinders hydraulically blocked or pressurized against movement exceptfor the cylinder being pressurized. If full tray movement, e.g., tosecond pallet position 47 (FIG. 2) is to be had, then simultaneouslywith the pressurizing of cylinder 365 the left end of cylinder 360 ispressurized, rod 360a remains stationary (cylinders 350 and 355 blocked)but the cylinder 360 shifts to the left (see arrow) carrying cylinder365 with it to the left since they are welded together. This causescontinued shifting of rod 365a additively to the left. The position ofplate 300 is thus to its maxium shift leftwards as shown in position Cvia rod 365a and connection 395.

Referring now to FIG. 15, position A of the hydraulic system again showsthe neutral position, with centralized drive plate 300. However, bypressurizing the left end of cylinder 355, rod 355a moves to the right(see arrow) into cylinder 355, pulling rod 360a via pin 330 and T-slide305 therewith. Rod 360a is hydraulically blocked in cylinder 360 andtherefore pushes that cylinder along with attached cylinder 365 and itshydraulically blocked rod 365a to the right. Plate 300 is thus moved tothe right as illustrated in position B for a movement of tray 20 toposition 46' of FIG. 2. However, a simultaneous movement added theretocan be effected by pressurizing the right end of cylinder 350 causing itto shift to the right with respect to rod 350a which is fixed at itsouter end. Therefore, cylinders 350 and 355 shift to the right furthershifting (via T-slide 305) rod 360a, cylinder 360, cylinder 365, and rod365a to maximum extended position C for drive plate 300 for a full depthposition of tray 20 at 46, FIG. 2. The guiding function of T-bar 390will be evident in comparing positions A, B and C to maintain alignmentof the multi-cylinder floating array with the drive plate.

Referring to FIG. 16, the chain and sprocket extending arrangement forthe drive plates 300, 305, and 310 and angle beams 290 isdiagrammatically illustrated in conjunction with the hydraulic systemcomprising the four cylinders 350, 355, 360 and 365.

The neutral position of the cylinders wherein the tray 20 is centralizedwith respect to the tower is illustrated at position A. Thus allcylinders are under pressure in order to positively lock the tray in thecentral position. Pressure maintenance for locking the position ispreferred as, in fact, it is preferred also for the extended position ofsub figures B and C even though hydraulic blocking by valving in a wellknown manner could be used. Referring to the diagrammatic componentsshown at position A, the drive plate 300 will be noted as being fastenedat 400 to the piston rod 365A whereas at the other end of the hydraulicsystem array, the piston rod 350A is connected to the elevator frame at395, all as herein before described and illustrated in the several viewspreceding, e.g., FIGS. 14 and 15.

Suitably fastened to the elevator frame (FIGS. 9, 10A, 10B) as by aclamp or other member, at 415, on a plate 416 wherein such plate isfastened to the cross plates 245c and 245d, is a sprocket chain 410which passes around a sprocket wheel 410B carried by and just forward ofthe right edge of plate 300. Chain 410 is then fastened to the left endof and on the underside of drive plate 305 at 445.

Reference character 445 representative fastening locations for chains,one above and one below the drive plate 305 (FIG. 9) as set forth below.

From the upper surface of plate 300 to a sprocket 410D carried at theedge of drive plate 305 is a chain 411 the other end of which chain isfastened to the lower surface of the plate 310. Finally, a third chain412 is fastened at 445, upper surface of plate 305, passing around thesprocket 410f for securement at 420 with one of the iron angle beams 200which carried the tray 20.

All flexible members are thus described as chains although, of course,it will be understood that equivalent components such as cables,pulleys, belts, etc. could be used. All sprocket wheels are carried oncors extending just beyond the edges of the drive plates to which theyare secured, e.g., the sprocket wheel 410f (FIG. 10B) carried at theedge of plate 310.

All chains shown in solid lines (FIG. 16A), and just described, effectpositioning of the several plates and ultimately the tray 20 to theright to position 46, FIG. 2, for the chain position B, FIG. 16, andreference may be had to FIG. 15 for comparison therewith insofar as thehydraulic system is concerned. Either position 46 or 46' can be thusreached and the tray 20 held locked by full actuation of the cylinder orcylinders required for the desired extent of tray motion and subsequentmaintenance of pressure to hold the position.

In the same manner, position of the tray to the first or second palletpositions for handling of pallets to positions 47 or 47' (FIG. 2) isaccomplished by simple reverse action effected by the chains 410', 411',and 412' and the hydraulic positioning shown for the cylinders atposition C of FIG. 14, such chains being shown dotted in the position A,FIG. 16. For neutral tray position the opposite set of chains are used,in either case.

Chain 410' is frame fastened at 425 to cross plate 245c and passesaround the sprocket 410a at the left end of plate 300 (FIG. 10A) toterminate at the fastening 445' below plate 305. A second chain 411' issecured at the upper surface of 440' of plate 300 and passes aroundsprocket 410C to fastening at 450' at the lower surface of plate 310.Finally, a chain 412' fastens at 445' to the upper surface of plate 305and passes around the sprocket 410E to be fastened at 430 to the otheriron angle beam 200.

In general it will be noted that all of the drive plates carry sprocketsat their ends and that the two series of chains are a reversed in layoutgeometrically.

In operation, when the plate 300 is hydraulically motivated in eitherdirection it exerts a thrust via the sprocket wheel at one end or theother against the chain engaged therearound and for each increment ofhydraulically driven travel of plate 300, the plate 305 moves outwardsin the same direction for twice the distance of plate 300, in accordancewith well known principles. Of course, the angularity as shown in FIG.16A of the sides of the chain 410 or 410' makes a slight reduction inexact doubling of the movement, but this if of no significance since itis not present in the device and only a very large angle wouldappreciably reduce the doubling of the distance. However, plate 305being thus driven in either direction does not double the travel ofplate 310, nor does the travel of plate 310 double the travel of beams290 and tray 20, but merely give single increment additive travel ateach step. The reason for this is that the plate 300 must move in thesame direction in order to actuate either chain series and thissubtracts from relative increment increases between the remaining platesand the tray because their drive chains do not have fixed ends as dochains 410 and 410'. However, the actual travel of tray 20 is four timethe travel of the plate 300.

The compactness and versatility of the tray transport power drivemechanism comprising hydraulic cylinders, and chains or other suitablebelt-like members, will be apparent from the above description and thedrawings. Thus, the tray and the coplanar nested beam pair supports arereversible and pass through their own rest positions in eitherdirection. The hydraulic cylinders are all coplanar in a flat arrayintegral unit floating between drive plates and beams and having limitedrocking movement as the beams move. All chains and sprocket wheels arealso disposed in this beam plane and are located in the spacing betweenthe innermost beam pair 290. All sprockets are carried on shortoutrigger arms at the edges of the drive plates, and most of the chainspass between the webs of such plates. In particular, space is saved byskewing the sprockets 410c and 410d at the edges of drive plate 305, thechains 411 and 411' passing respectively therearound on both sides ofthat plate.

Thus, what may be termed "left" and "right" telescopic chain systemshave chains and sprockets in reverse but symmetrical series, the chainsof each system being individually secured in sequence from the elevatorframe 226 to the final beams 290 via the drive plates 300, 305, 310whereby sequential pull is exerted on the next succeeding plate (orultimately beams 290 by virtue of thrust exerted by a proceeding plate.Except for chains 410 and 410', which have fixed reaction connections,the reaction connection for each chain is on the drive plate precedingthe drive plate that carries the thrust sprocket for that chain.Accordingly, the initial thrust of plate 300 is transformed into aseries of alternate chain tensions and plate thrusts via the sprocketsto simultaneously telescope the beams by a succession of pulling forceswhich are virtually simultaneous in either left or right direction asviewed on FIG. 2, depending on which of the dual chain systems is beingactuated, a matter of the direction of hydraulic drive of plate 300.

THE POSITION INDICATING SYSTEMS

While in commercial practice the stacker crane described herein would befully automatically controlled by a system which does not form part ofthe present application. It can be manually controlled, if desired, bymore personal skill in positioning the tower and the tray. However, as apractical matter for precise positioning mechanical position indicatingmeans should be utilized, particularly since the tower may have ahorizontal traverse of several hundred feet and a height of as much as60 feet. Obviously it would be quite impractical for an operator to bepresent at the tower location in order to precisely control it and tocontrol the tray for the precise positioning needed.

Accordingly, referring to FIG. 4A, an indicating sensor and signaltransmitter arrangement for vertical movement is illustrated whichcomprises a shaft angle encoder 500 secured to the elevator on anoutrigger arm 505 and coupled to a sprocket wheel 515. A fixed sprocketchain 520 is carried on the corner angle iron 145. As the elevator movesvertically the sprocket wheel is caused to rotate by the fixed chainwhich rotates the encoder. The encoder is a conventional rotary type,for example, Nordon type ADC-13-BNRY-E, style 46, which by conventionalelectrical connections is capable of sending a binary signal of distinctcharacter for each quarter inch of vertical movement of the elevator.Such binary signals can be continued in conventional readout aparatus toapprise an operator of the vertical position of the tray elevator andthe tray 20. The operator can thus control motor 80 to reach a selectedstorage cell level. Of course, the tray would be initially positioned acouple of inches below the cell support rails 48 for picking up a palletor initially positioned a couple of inches above for depositing apallet, prior to being horizontally extended either to first or secondpallet positions for either purpose. The final slight movement of thetray up or down would be under slow motor control, either by gearing, orcircuitry or motor construction, all long known, and with the aid of theindicating system readout in an obvious manner.

Referring now to FIG. 6A, the same arrangement is used for indicatingthe precise horizontal position of the tower wherein the shaft angleencoder 550, the same type as encoder 500, and sprocket wheel 560 arecarried on the arm 39 to engage the chain 565 fixed lengthwise to theguide rail iron angle 36 fixed to the storage rack construction. Thus bythe vertical and horizontal indicating systems an operator would knowthe position of the tower with respect to the length of the storage gridand could thus precisely position the tower in front of a selectedstorage cell as well as positioning the tray vertically, it beingunderstood that suitable slow speed control motors 70 and 80 areutilized or other means for effecting "creep" are present.

It is, of course, necessary for an operator too far removed from a trayto observe it totally, to have an indicating system so that he will knowthe exact position of the tray 20 with respect to the tower. Referringto FIG. 8, such a system is illustrated comprising a chain reel 600carried by a fixed beam 275 and having a sprocket chain 610 maintainedin tension by a spiral spring (not shown) within the reel which chainextends around a sprocket wheel 615 carried at the outer end of plate245d and thence passes between a pair of rollers 620 and 625 carried bythe fixed beam and having an end 630 fixed to the tray 20 (FIG. 7).Accordingly, regardless of the direction of motion of tray 20 asindicated by the reversed arrows (FIG. 8), the sprocket chain will bepulled in the same direction from the reel. This causes rotation ofsprocket wheel 615 to actuate the arm of a switch 640 between contactpositions such that a first position of the switch arm gives a signal toapprise the operator that the tray is in central position, whereas whenthe tray starts to move the switch arm moves to a successive contactposition indicating that the tray is in first pallet position, or theswitch moves to a further contact position to signal that the tray is insecond pallet position, corresponding to positions 46, 47 or 46', 47'.

Details of the switch mechanism are not necessary, but obviously asuitable gearing between sprocket wheel 615 and the switch 640 would beutilized so that full traverse of the tray in either direction wouldmove the switch arm through the several contacts and return. The signalsused could be three lights of different colors wired to the switch in anobvious manner.

CONTROLS

From all the preceding, it will be apparent that any conventionalcontrol system can be utilized, for example, the motors 70 and 80 can beenergized simultaneously and either the motors 70 or the motor 80controlled to creep when the operator is apprised by readout that thetray is close to the proper respective horizontal or vertical position,the respective motors being stopped by braking when the readoutindicates precise positions, i.e., within 1/4 inch with the particularencoders used. Similarly, the hydraulic cylinders 255 (FIG. 7) forcentralizing the pallet would be operated by solenoid valves and thiscould be done at the time the pallet is picked up on the tray 20 from aconveyor, or at any time prior to actual insertion in a cell.

The hydraulic cylinders 350, etc. (FIGS. 14, 15, 16) for the traytransport telescopic mechanism are likewise solenoid valve operated and,in fact, such hydraulic system requires only respective solenoidoperated multiway valves all of conventional construction and hook-up,although, of course, any suitable hydraulic circuitry control systemcould be utilized. In an operative embodiment conventional solenoidspool valves as made by Vickers Div. of Sperry-Rand Corp. were used,Model DG 454-012A-50 connected to a pressure source and sump and to thecylinders, all in the usual manner and carried by the tower andelevator, whereby one end of each cylinder was always under pressure(position A, FIG. 14) to maintain the tray 20 in central position untilit is desired to actuate it. Such valves are spring biased to an initialposition for that effect, by spring biased return from an actuatedposition.

It will of course be appreciated that various obviously requiredcomponents are omitted for the sake of clarity, such as flexible hosesto hook up to the hydraulic cylinders and electric cables for themotors. Such connecting components are well known in the field, and as amatter of design, various types are usable. Likewise, as a matter ofdesign, the solenoid valves for the various sets of hydraulic cylinderscan either be at a fixed control point or carried by the tower. Further,power control circuitry and switching circuitry likewise could be at afixed control point, but preferably is carried by the tower at thecontrol panel 60 (FIGS. 1, 2).

The compactness and practicality of the invention should be apparentfrom the description and the drawing, and in particular, the exceedinglysimple power drive means for telescopically transporting the trayreversibly via flexible loop members such as sprocket chains which rollaround sprocket wheels, all within the vertical and horizontal planesdefined by the innermost pair of beams 290. Thus by providing dualsystems of what might be called zig-zag orders of sequentially connectedchains, a very economical yet highly effective arrangement is provided.

Having thus described the invention, I am aware that variousmodifications can be made within the spirit of the concept and thereforedo not seek to be limited to the exact illustration herein.

I claim:
 1. A stacker crane tray mechanism comprising a tray and movablesupport means therefor, said support means comprising a plurality ofpairs of telescopically articulated beams;one beam pair being attachedto said tray and one other beam pair being relatively fixed and withrespect to which fixed beam pair all other beam pairs are telescopicallymovable; there being beam pairs intermediate said fixed beam pair andthe beam pair attached to said tray, and each beam of said intermediatebeam pairs having a guide channel extending in to one face thereof andhaving guide rollers extending from the other face thereof directlyopposite the respective channel thereof; wherein all said beam pairs aretelescopically connected by rollers of beam pairs extending into guidechannels of immediately adjacent beam pairs; drive plates secured torespective movable beam pairs for effecting telescopic movement thereof;and each having a central channel with a flange extending laterally oneach side of the respective channel and secured to a beam of arespective pair; said channels being nested and having spaces therebetween and said drive chain means being disposed in said spaces; saiddrive plates being sequentially coupled by said drive chain means sothat driven movement of a first of said drive plates effectsprogressively extended movement of the remainder of said drive platesand the respective beam pairs, to drive said tray.
 2. A stacker cranetray mechanism as set forth in claim 1;said chain means comprising aseries of chains for a particular direction of telescopic movement ofsaid beam pairs and tray; wherein a first chain has a relatively fixedend and passes around bearing means carried by said first drive plateand is fastened to a next adjacent drive plate; said next adjacent driveplate and all drive plates thereafter up to a final drive plate beingalternately fastened to each other in pairs of alternate plates by arespective chain passing around bearing means carried by a drive platebetween each pair of alternate plates; a final chain being fastened to adrive plate next before said final drive plate and to said tray andpassing around bearing means carried by said final drive plateintermediate said next to final drive plate and said tray.
 3. A stackercrane tray mechaism comprising a tray and reversibly movable supportmeans therefor to movably support said tray in being driven to either oftwo selective positions in either of two directions;said support meanscomprising a plurality of articulated beam means one of which isattached to said tray and another of which is relatively fixed and withrespect to which fixed beam means all other beam means are movable andare drivingly connected to carry said tray to said selective positionsupon a first of said beam means being driven; and hydraulic drive meanscomprising a plurality of double-acting hydraulic cylinders arranged inpairs having respective pistion rods; a cylinder of each pair beingintegrally connected to a cylinder of another pair; one rod of each pairbeing integrally connected to a rod of another pair; means whereby theother piston rod of one of said pairs of cylinders has an end relativelyfixed with respect to said relatively fixed beam means, and the otherpiston rod of the other of said pairs of cylinders is drivinglyconnected to said beam means; means interconnecting said beam meanswhereby movement of said first beam means effects motion of all saidmovable beam in the same direction; whereby selective pressurization ofsaid cylinders effects motion of said tray to a selective position in adirection dependent upon direction of pressurization of said cylinders.4. A stacker crane tray mechanism as set forth in claim 3;said driveplates each comprising a channel portion having extending flanges towhich the beams of a respective beam pair are secured; said channelportions being nested and said hydraulic cylinder means housed withinthe innermost channel connected to drive said first drive plate.
 5. Astacker crane tray mechanism comprising a tray and support meanstherefor, said support means comprising a plurality of pairs oftelescopically articulated movable beams and a relatively fixedsupport;a first movable beam pair being attached to said tray and a lastmovable beam pair having support on said relatively fixed support andwith respect to which support all movable beam pairs are telescopicallymovable; beam pairs intermediate said first and last beam pairs; guidechannels in, and guide rollers on, respective adjacent faces of thebeams of said pairs, whereby all said beam pairs are telescopicallyconnected by rollers extending into guide channels of immediatelyadjacent beams; a drive plate for each movable beam pair and secured tothe beams thereof; chain means connecting said drive plates whereby saidbeam pairs are reversibly movable to support said tray in a translatedposition when said last beam pair is driven; hydraulic drive meanscomprising two pairs of double acting hydraulic cylinders; a cylinder ofeach pair being integrally connected to each other and said connectedcylinders being thus movable in unison; said cylinders having respectivepiston rods and a piston rod of one said pair of connected cylindersbeing integrally connected to a piston rod of the other said pair ofconnected cylinders; means whereby the other piston rod of said one pairof connected cylinders has an end relatively fixed and whereby the otherpiston rod of said other pair of connected cylinders is drivinglyconnected to the drive plate of said last beam pair; whereby selectivepressurization of said cylinders effects selective motion of saidconnected cylinder pairs and piston rods to actuate said last nameddrive plate to a selective extent and in a direction dependent upondirection of pressurization of said cylinders for driving said tray bysaid chain means and the drive plates of said beam pairs.
 6. A stackercrane tray mechanism comprising a tray and a movable support thereforcomprising a plurality of telescopically movable articulated beamshaving a support means;a first of said beams being attached to said trayfor support thereof, and a last of said beams being movably carried bysaid support means; beams intermediate said latter beams; all said beamssequentially supporting each other in the course of telescopic movement,and support and guide means intermediate said beams for effecting saidsequential support; a tensile drive means sequentially coupled to saidbeams so that driven movement of said last movable beam effectsprogressively extended movement of the remainder of said movable beamsto extend and support said tray; hydraulic cylinder means comprising twopairs of double acting hydraulic cylinders each pair being integrallysecured to each other and said pairs having relative movement withrespect to each other; said cylinders having respective piston rods; arod of one cylinder pair being connected to a rod of another cylinderpair; the other rod of said one cylinder pair having an end relativelyfixed and the other rod of the other cylinder pair being drivinglyconnected to said last movable beam; whereby selective pressurization ofsaid cylinders effects selective motion of said cylinders and pistonrods to actuate said beams bidirectionally and to either of twopositions in either direction.
 7. A stacker crane tray mechanismcomprising a tray and movable support means therefor, said support meanscomprising a plurality of pairs of telescopically articulated beams;onebeam pair being attached to said tray and one other beam pair beingrelatively fixed and with respect to which fixed beam pair all otherbeam pairs are telescopically movable; the beam pairs intermediate saidfixed beam pair and the beam pair attached to said tray having guidechannels at one face thereof and guide rollers at the other facethereof; wherein all said beam pairs are telescopically connected byrollers of beam pairs extending into guide channels of immediatelyadjacent beam pairs; drive plates secured to respective beam pairs foreffecting telescopic movement thereof; said drive plates extendingtransversely of the path of movement of said beam pairs and havingparallel center sections horizontally spaced; said center sections beingnested and having spaces therebetween and drive chain means beingdisposed in said spaces; said drive chain means and said drive platesbeing sequentially coupled by said drive chain means so that drivenmovement of a first of said drive plates effects progressively extendedmovement of the remainder of said drive plates and the respective beampairs, to drive said tray.
 8. A stacker crane tray mechanism as setforth in claim 7, said drive plates being reversibly movable;andhydraulic drive means comprising a plurality of double acting hydrauliccylinders secured in pairs, one pair being connected to another pair byconnection of a piston rod of each of said pairs to each other; thecylinders of each pair being connected to each other and the respectiverods thereof extending in opposite directions; means whereby the otherpiston rod of one of said pairs has an end relatively fixed with respectto said relatively fixed beam pair and the other piston rod of the otherof said pairs is drivingly connected to said first drive plate; wherebyselective pressurization of said cylinders effects motion of one or bothof said piston rods to actuate said first drive plate to a selectiveextent and in a direction dependent upon direction of pressurization ofsaid cylinders.